An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth âs surface. They are among the flattest, smoothest and least explored regions on Earth.
Jim Beckwourth. On this day in 1844, Jim Beckwourth discovered a path through the Sierra Nevada Mountains that now bear his name. Beckwourth Pass on U.S. Alt 40 between Reno, Nevada and Sacramento, California made overland travel to the gold fields of California. Tweet.
Brenner Pass (an Alpine mountain pass connecting Innsbruck in Austria with Bolzano in Italy that has long been a route for trade and for invasions). Cumberland Gap (a pass through the Cumberland Mountains between Virginia and Kentucky that early settlers used in order to move west).Donner Pass (a mountain pass in northeastern California near Lake Tahoe; site where in 1844 some members of an emigrant party survived by eating those who had died).umberland Gap (a pass through the Cumberland Mountains between Virginia and Kentucky that early settlers used in order to move west). Donner Pass (a mountain pass in northeastern California near Lake Tahoe; site where in 1844 some members of an emigrant party survived by eating those who had died).